Band Suppression Module for Distributed Antenna Systems
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Solution Overview
Problem
Distributed Antenna Systems (DAS) face challenges in efficiently managing public safety bands, particularly in scenarios where interference occurs, requiring expensive redundant equipment for emergency situations, and existing solutions involve separate communication paths for each band, which is costly and inefficient.
Innovation Solution
Implementing a band suppression module that selectively attenuates public safety bands to levels considered acceptable as spurious emissions, allowing private safety bands to remain operational without the need for redundant equipment, by using switchable RF components and control circuitry to manage signal paths.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If separate communication paths are provided for each band in remote antenna units, then public safety band interference is avoided, but system cost increases significantly due to redundant expensive equipment
Solution Approach 1:
The patent extracts the public safety band signals from the combined signal path using a diplexer, separating them into a dedicated path that can be independently controlled. This allows the public safety band to be suppressed or transmitted without affecting private safety bands, avoiding interference while sharing common equipment.
Solution Approach 2:
The patent implements dynamic control of the public safety band transmission through a switch that can selectively connect or disconnect the public safety path. This allows the system to adapt between normal operation (public safety suppressed) and emergency operation (public safety activated) modes, reducing idle equipment costs while maintaining interference avoidance.
2Reliability
If public safety band is continuously transmitted in above ground segments, then emergency coverage is maintained, but interference with local public safety base stations occurs
Solution Approach 1:
The system dynamically switches between suppressed and transmitted states for the public safety band based on operational conditions. During normal operations, the public safety band is suppressed to avoid interference. During emergencies, the switch activates the public safety path to provide necessary coverage, maintaining reliability while preventing harmful interference.
Solution Approach 2:
The system preemptively suppresses the public safety band in above-ground segments during normal operations to prevent interference with local base stations. This preliminary action avoids the harmful effect before it can occur, while the capability to activate remains prepared for emergency situations.
3Reliability
If redundant power amplifier modules are installed for each band, then emergency public safety operation is ensured, but equipment cost and complexity increase
Solution Approach 1:
The patent makes the common power amplifier and antenna serve dual purposes by using a diplexer to separate public safety and private safety bands. The same hardware infrastructure supports both functions, with the diplexer routing signals appropriately. This eliminates the need for separate redundant power amplifiers while ensuring emergency capability through selective activation.
Solution Approach 2:
The system dynamically reconfigures the signal path using a switch that can route private safety signals directly to the common power amplifier, or route public safety signals through the diplexer to the same power amplifier. This dynamic switching allows one power amplifier to serve both bands with appropriate isolation, eliminating redundant equipment while maintaining emergency operation capability.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables cost-effective and efficient switching of public safety bands on or off in remote antenna units, reducing idle equipment and maintaining operational private safety bands, thus enhancing DAS performance without the need for redundant expensive components.
Implementation Method 1
a band suppression module that selectively attenuates public safety bands to levels considered acceptable as spurious emissions
Data Source
Figure 1
Figure 1A~1C
Figure 2
AI summary
In one embodiment, a distributed antenna system comprises at least one master unit; at least one remote antenna unit coupled to the master unit and comprising a power amplifier to radiate a remote downlink radio frequency signal, the remote antenna unit further configured to receive a remote uplink radio frequency signal from at least one antenna, the remote downlink radio frequency signal comprises first and second downlink frequency bands and wherein the remote uplink radio frequency signal comprises first and second uplink frequency bands; a band suppression module comprising: a controller; an uplink band suppression element configured to apply an attenuation to suppress the first uplink frequency band in response to a signal from the controller; and a downlink band suppression element configured to apply an attenuation to suppress the first downlink frequency band in response to the signal from the band suppression controller.